GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 XLR 🢒 Accessories 🢒 Navigation Systems 🢒 DTC B1271

Circuit Description

This DTC is generated by the module when the Theft Lock is activated. This occurs when the VIN as received over the class 2 communication circuit and the VIN as stored in the module memory do not match. This also occurs when no VIN is received over the class 2 circuit. The only circuit required is the class 2 communications line.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1271 Theft Locked

Conditions for Running the DTC

This test is run every 300 milliseconds.

Conditions for Setting the DTC

This DTC is generated by the module when the VIN as received over the class 2 communication circuit and the VIN as stored in the module memory do not match. This also occurs if no VIN is received over the class 2 circuit. This DTC test runs when the radio changes from OFF to ON.

Action Taken When the DTC Sets

The radio does not function. The radio will display Locked -- THEFTLOCK Active.

Conditions for Clearing the MIL/DTC

Re-calibration with the correct calibrations for the vehicle and cycling the radio to OFF then to ON will clear the DTC if there is no damage to the radio.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool clear the radio theft information by selecting VIN Relearn under Radio.

Does the DTC Reset?

Go to Step 3

System OK

3

Replace the radio. Refer to Control Module References .

Did you complete the replacement?

System OK

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